Decomposing Fungi

There are over 200 species of fungi at Muir Woods like these brown mushrooms growing out of this wet, moss-covered log.
Decomposers break down decaying organic material, like this false turkey tail growing on this log.

Stephanie Weinstein/ NPS

What do you call a fungus that makes music? A decomposer!

Fungi that get their nutrients from breaking down decaying organic material are called saprotrophs. Saprotrophs act as decomposers in the forest. They play a big role in breaking down wood and other debris to recycle nutrients back into the soil. They are very important to the redwood forest ecosystem. Without them, all the fallen wood, leaves, and other organic matter would pile up on the forest floor and Muir Woods would be nothing but a wood pile! 

Consider visiting Muir Woods during the winter when it rains. Take a moment to notice the signs of decomposition going on around you.  Observe the fallen trees, the soft beds of redwood needles, and piles of bay laurel leaves on the ground. Take in the rich earthy smell of the soil and rain around you. All these wonderful sights and smells are the product of the fungi working very hard at their job of being decomposers!

We have many species of saprotrophic fungi here at Muir Woods but here are some of the most common: 

 
Turkey Tail, like this one growing among a bed of greenery, is very common at Muir Woods but easy to confuse with false turkey tail. You can distinguish the two species by the presence of pores on the underside of Turkey Tail. NPS Photo.
Turkey Tail, like this one growing among a bed of greenery, is very common at Muir Woods but easy to confuse with false turkey tail. You can distinguish the two species by the presence of pores on the underside of Turkey Tail.

NPS.

Trametes versicolor

Common name: Turkey Tail
Description: Known for its bright colors in wide rings that resemble a turkey’s tail. White or creamy underside is covered in many small pores. 
Ecology: Very common in Muir Woods, especially on dead hardwoods in the winter but can be found year round

 
Artist’s Conk, like this one growing out of the side of a log here, can grow quite large and some can support the weight of a grown adult! NPS Photo.
Artist’s Conk, like this one growing out of the side of a log here, can grow quite large and some can support the weight of a grown adult!

NPS.

Ganoderma applanatum

Common name: Artist’s Conk
Description: Your classic shelf mushroom that can grow quite large. Has a large brown to grey cap and a crisp white pore surface.
Ecology: Found in hardwoods and conifers and causes white rot in dead trees. Bruises brown and can retain the bruise for many years, so some people make beautiful etchings and art out of them! 

 
Oyster mushrooms like this one growing out of this tree, are very common in Muir Woods and you can find them on hardwoods, like oaks. NPS.
Oyster mushrooms like this one growing out of this tree, are very common in Muir Woods and you can find them on hardwoods, like oaks.

NPS.

Pleurotus ostreatus

Common name: Oyster mushroom
Description: This easy to recognize mushroom has broad, wavy caps and grows in off-white to brown clusters. 
Ecology: Very common, can be found in late fall through winter growing on hardwoods.

 
Sulphur tuft, like this cluster of mushrooms growing on this dead log here, is abundant in the Bay area and feels right at home on the fallen logs here in Muir Woods. NPS Photo.
Sulphur tuft, like this cluster of mushrooms growing on this dead log here, is abundant in the Bay area and feels right at home on the fallen logs here in Muir Woods.

NPS.

Hypholoma fasciculare

Common name: Sulphur tuft or clustered woodlover
Description: Distinctive yellow-brown cluster mushroom.
Ecology: Found on dead hardwood or conifer logs and stumps. Very common in the Bay area and poisonous.  

 

This list of decomposers are a few of many species within Muir Woods. This is by no means a comprehensive list and there are many more to see!

While there are several edible species listed here and found throughout the redwood forest, it is important to note that mushroom foraging is not allowed at Muir Woods. Please use the information provided only as a resource about the kind of fungi that can be seen in the park. This information is not intended as an identification guide. It is not enough for identifying wild mushrooms to forage. Identifying wild mushrooms can be extremely difficult and can be deadly if done incorrectly. Please take only pictures of the beautiful mushrooms you see at Muir Woods. Let’s leave the fungi alone to continue their role in breaking down vital nutrients to nourish the redwoods. 



For Further Reading: 


Arora, David. Mushrooms Demystified: a Comprehensive Guide to the Fleshy Fungi. Ten Speed Press, 1986.

“Behind the Scenes: How Fungi Make Nutrients Available to the World.” Energy.gov, www.energy.gov/science/articles/behind-scenes-how-fungi-make-nutrients-available-world.

Stamets, Paul. Mycelium Running: How Mushrooms Can Help Save the World. Ten Speed Press, 2005.

“Decomposing Fungi.” National Parks Service, U.S. Department of the Interior, www.nps.gov/mora/learn/nature/decomposing-fungi.htm. 

Last updated: September 16, 2021

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